Beyond date of birth, what other personal information are we giving away on social network sites? In a talk a few weeks ago at the 2010 RSA Conference, security researcher Nitesh Dhanjani explored some non-traditional ways social networking could be used to profile individuals. He says just by studying your social networking presence one can identify, for example, pending business deals.
Dhanjani , who says his exploration is just a hobby, says he created a LinkedIN account for friend who didn’t yet have an account—we’ll call him “Jack”— then invited a mutual friend to join Jack’s LinkedIn network. Within a short time, Jack acquired over 80 connections. What’s surprising here, says Dhanjani, isn’t that people linked to this fraudulent LinkedIn profile, but what information he as an impostor was able to glean about Jack’s sphere of influence and business.
For example a competitor cybersquatting as Jack could now see Jack’s clients. And, if Jack’s company was about to be acquired (and that information was not yet public), an outsider might further see a recent influx of new connections from several people at a rival organization. The lesson here is to establish a presence on the major social networks, if only to stake claim to your name and reputation.
Even legitimate social networks can be hacked: someone could friend you just to get access to someone else you know. A law enforcement officer could be seeking information on a person of interest who happens to be part of your social network. According to the Electronic Freedom Foundation, social networks are being used by federal investigators, and last week the privacy organization released a 38-page PDF training course (obtained through the Federal Freedom of Information Act) that the EFF said was used for conducting investigations via social networks. While federal agents can’t legally pretend to be someone else, they can request to be your friend and thus see all your posts, as well as those of others in your network. The EFF has been studying the privacy issues associated with this new form of surveillance. Often we accept people into our social networks by extension of trust, i.e. a friend of a friend, so a good rule of thumb might be to question how well you really know a person before accepting a new friend request.
But one doesn’t have to join a social network to define your social network.
In his RSA presentation Dhanjani also demonstrated how outsiders can use publicly available social network information to define spheres of influence around a targeted individual. Popular social networks display the top 8 friends for a person as means of identifying exactly which John Smith you’re currently looking at. By comparing the 8 friends on MySpace with the sample 8 friends on FaceBook, Dhanjani says he can map who are the critical contacts for the targeted individual. And by going one step further, by looking at the friends of those friends, one can further map who has the most influence with a targeted individual, their “posse” if you will, and do so without joining the network. A hacker using social engineering could then contact the targeted individual and say “Jane said I should contact you about Alice.”
Some may see all this as nothing new. Kevin Mitnick pioneered social engineering years ago. But now the means to profile someone is much more convenient. Be careful who you know and what you post online. You never know who might be listening.
Orginally published in Forbes.com